Vibronic Spectra of Diatomic Molecules and the Birge-Sponer Extrapolation©
Theresa Julia Zielinski Department of Chemistry, Medical Technology, and Physics Monmouth University West Long Branch, NJ 07764-1898 United States mail to: tzielins@monmouth.edu
George M. Shalhoub Department of Chemistry La Salle University Philadelphia, PA 19141-1199 United States mail to: shalhoub@lasalle.edu
Abstract
The goal of this document is to examine the potential energy curve for both the ground and excited state of an electronic transition in order to set the stage for a Birge-Sponer determination of the D0 and De dissociation energies of the excited state of a diatomic molecule from experimental UV-vis spectral data. This document takes advantage of the live symbolics and optimize features of Mathcad 6.0+ to present a derivation of the Birge-Sponer equations. The document contains ample student exercises to foster reflection and learning of the spectroscopic concepts. After using this document students will be able to: explain the relationship between the potential energy curves for excited and ground states in a molecule; explain the significance of each parameter in a Morse potential energy function; and use a Birge-Sponer plot to determine dissociation energy of an electronic excited state of a diatomic molecule. This document will prepare students for analysis of the vibronic spectrum of iodine or some other diatomic molecule. The Iodine Spectrum document, IodineSpectrum.mcd, is the companion template for the analysis of the UV-vis spectrum of a diatomic molecule. This document is one of a suite of documents treating the vibronic spectra of molecules. The other documents in the set are: MorsePotential, Introduction to Franck-Condon Factors, and the Iodine Spectrum. When used together these documents form a powerful integrated collection of concept builders for students studying spectroscopy in a Junior or Senior college level quantum chemistry course.
Commentary
Editor's Commentary
Keywords
Audiences: Upper-Division Undergraduate Pedagogies: Computer-Based Learning Domains: Laboratory Instruction, Physical Chemistry Topics: Mathematics / Symbolic Mathematics, Quantum Chemistry, UV-Vis Spectroscopy
Documents
File Name Description Software Type Software Version BirgeSponer.mcd Mathcad Computational Document Mathcad BirgeSponer.pdf Read-Only Document BirgeSponerB.pdf Read-Only Document BirgeSponerB.mw Maple V Computational Document Maple V BirgeSponerAV.pdf Read-Only Document BirgeSponerA.mw Maple V Computational Document Maple V JCE Subscribers only: name and password or institutional IP number access required.
Citations
Shalhoub, G. M.; Zielinski, T. J. J. Chem. Educ. 1998 75 1192.
Comments to: Theresa Julia Zielinski at tzielins@monmouth.edu and George M. Shalhoub at shalhoub@lasalle.edu
©Copyright 1998 Journal of Chemical Education